Acting on informants' tips that the deadly drug originated from the Mott St. location, cops arrested the four suspected dealers -- two men in their 50s and a man and a woman in their 20s -- at around 7 p.m. and seized more than 350 bags of heroin.

Law-enforcement officials said a hypodermic needle and two glassine envelopes containing what is believed to be heroin were found in the apartment on Bethune Street in the West Village neighborhood of Manhattan.